Multiple conductor composite cables, such as the 9461-0013 cable manufactured by The Rotor Tool Company, Cleveland, Ohio, are widely used for transmission of power and control signals to, for example, automatic assembly tools such as nut runners, and connection to power monitoring and control devices such as the Rotor Tool Brushless DC Torque Angle Controller or other control devices such as disclosed in U.S. Pat. No. 5,117,919 incorporated herein by reference. Such cables are typically constructed by disposing a plurality of relatively small gauge control signal wires radially about center axially disposed relatively larger gauge power transmission cables, as generally shown in FIG. 1. In order to electrically insulate each of the individual cables, separate sheathings made of polyurethane or PVC are used, in addition to the individual sheathings of each cable, to bundle and insulate the cables in the desired arrangement.
A significant problem encountered with this approach when executed with insulative/non-metallic sheathings is that magnetic flux generated by the centrally disposed power cables propagates radially outward across the surrounding signal cables, causing interference in the control signals and consequent loss of accuracy of signals used to monitor and control a tool to which the cable is attached, as described in the '919 patent. In prior art cables, the use of tin/copper sheathings about the power cables does not block electrical interference from the outer signal wires.